If I understand your definition of looping and it is not truly eye lashing (which would be a result of tension) - things that I would try would be changing to a fresh needle or possibly changing to a different size (up or down one size from whatever it is you're currently using) and or trying a thread net over the spool/cone you're using. Another thing to check is for a teensy tiny bit of lint in the bobbin area, or a nick on the needle plate. These are all things that have caused looping for me!
Good luck!